Re: anyone running GPS clocks in Southeastern Georgia?

["Robert E. Seastrom" <rs () seastrom com>]

Joel Jaeggli <joelja () bogus com> writes:

> > Sure, and there are GPS-steered Rb clocks in telco-land too as well as
> > a ton of stuff I don't know about yet until everyone else here chimes
> > in; it's just that NTP is highly visible to NANOGers.
>
> if your high quality stratum one time source isn't capable of
> free-running for a little while then it's not really high quality...

<cough> no comment.  :-P

> you can of course test this simply by disconnecting the antenna. if the
> dilution of precision gets sufficiently high or the boise floor climbs
> above the signal then it should fail the gps out of the mix. our
> symerticoms have upgraded ocxo and backup geographically distant ntp
> sources in the pool to account for localized gps failure...
>
> I'm way to cheap to spring for the rubidum upgrade, the ocxo holdover is
> supposed to be 1ms a day.

Actually, if you are rolling your own (admittedly not what you're
doing when you buy Symmetricoms, but then again they are maintainable
in the field as opposed to the mad scientist stuff we have in our
basements), surplus Rb clocks are astonishingly cheap.  I have seen
used Datum LPROs (admittedly they are cheapies with higher Allan
deviation over short intervals than the PRS10) for circa $100.

-r